Grinding machine



March 3, 1931 RMERSHON 1,794,975

GRINDING MACHINE Filed Dec. 21, 1927 2 Sheets-Sheet l 10 44" I I' 45gwuewtoc 41 H 4% V RALPH MERSHON.

61am n1 1- March 3, 1931.

R. MERSHON GRINDING MACHINE Filed Dec.

2 Sheets-$heet 2 v Snow doe RALPH MERSHON.

351 WMM Qttoz neg Patented Mar; 3, I931 UNITED STATES OHIO PATENT OFFICERALPH -MERSHON, OF CINCINNATI, OHIO, CINCINNATI GRINDERS INCORPORATED,OF CINCINNATI, OHIO, A CORPORATION OF ASSIGNOR, BY MESNE ASSIGNMENTS, TO

emnnmemeofimn i Application filed December 21, 1927. Serial No. 241,544.

This invention relates to improvements in grinding machinery and hasparticular reference to 'a novel and improved structure especiallyadapted for use in production of I tapered work.

One of the principal objects of the present invention is the provisionof a structure forv the rapid successive production of a plurality offrusto-conical or tapered work pieces.

A further object of the invention is the provision of a machine whichmay be satisfactorily employed for the rapid and accurate formation ofthe seating face of an automobile valve or like article, in properconcentric release to the position determining stem thereof.

' A further object of the present invention is the provision of amachine operating in accordance with centerless grinding prlncipleswhich shall be capable of rapid forma- .tion of tapered or othernon-cylindrical surfaces on headedwork pieces or the like eitherseparately or in conjuction with the formation of concentricallydisposedv cylindrical surfaces on other portions of the work piece.

Other objects and advantages of the present invention should be readilyapparent by reference to the following speclfication'taken inconjunction with the accompanying drawings, and it is to be understoodthat I may make any modifications or variations in the specificstructural details hereinafter disclosed within the scope of theappended claims without departing from or exceeding the spirit of theinvention.

Figure 1 is a plan View of a machine embodying the present improvements.

Figure 2 is a fragmentary vertical section as on line 2-2 of Figure 1.

Figure 3 is a section as on line 33 of Figure 2.

Figure 4 is a fragmentary section as on line 4-4 of Figure 2. v

Figure 5 is a view of the work rest lock mechanism. 7

Figure 6 is a-fragmentary view illustrating a slightly modified formofthe invention in which a double grinding of the operation is performed.

Figure 7 is a transverse section on line In the drawings in whichsimilar characters of reference are employed to denote correspondingparts throu bout the several views the numeral 10 designates the bed ofthe machine having ways 11 for the rinding wheel slide 12 whose positionon the ed may be adjusted by screw- 13. This slide has journaled thereinthe vertical shaft 14 hearing at its upper end the grinding wheel 15formed with a beveled face 16 of proper angle to produce the seatingface 17 on valve 18.

Disposed in opposition to slide 12 is a second slide 19 mounted on theanti-friction bearings 20 to facilitate free in and out movementthereon. This slide is inwardly actuated as bysprings 21 interposedbetween the .rear of the slide and the lugs 22 on the bed.

i It will be understood that there is here provided a machine foroperation in accordance with established centerless grinding principlesto the extent that the grinding wheel is suitably driven as by belt 27and other power connections at a high or grinding rate of speed,preferably a surface speed of between 5000 to 6000 feet per minute andin the direction indicated by the arrow thereon in Figure 1 of thedrawin The regulating wfieel is also operated as by belt 28 fromsuitable power drive and in the direction indicated b the arrow thereonin Fi re 1. This whee however, is drivenat a s ow rate of speed tofrictionally engage and control the rate of rotation of a work piecewhen within a grinding throat between the twg wheels. kgn accoljinti1 of1:113 resilieni'.1 011' 'edin bac u o t ere 'atingw ee his wli eel hashe izapacity for slide in and out movement permitting of expansion ofthe normal adjustment of the grmdin throat when a work piece is firstforced into the throat while allowing the regulating wheel to follow upthe work and insure proper frictional engagement between the parts asstock is removed from the work piece. It will be evident that the springyielding feature as respects the regulating wheel may be utilized or notand that if preferred the regulating wheel may be adjusted to its exactproper position through use of the screw 23 when no yielding will takeplace.

In conventional centerless grinding prior to the present invention ithas been customary to place the work on' avstationary work rest in thethroat between the grinding and regulating wheels and to withdraw thework axially or parallel with the rest at the completion of grinding.

As distinguished from the previous practices, in the present inventionthe grinding and regulating wheels as shown occupy a horizontal,position. Carried by the bed intermediate the two wheel spindles is abracket 29 having a blade portion 30 adapted to slidably support a workcarrier 31. The carrier 31 is referably formed on its under side withtlie groove 32 to receive the guide rib 33 on the bracket and has theportions at the sides of the groove formed with the serration T -'orteeth 34 and 35. Guide plates 36 and 37 hold them in raised osition sothat they may more readily enter t e grinding throat.

In the operation of thepresent machine a series of work pieces areloaded into a fixture 31 which is then placed upon the bracket guide 30and placed in the direction of thethroat between grinding and regulatingwheels. To retain the work pieces in positionfor grinding and tosuccessively present locking w en in raised .position with the teethsame in operative position in the machine use may be made of a suitablefeed mechanism.

One such mechanism is illustrated in the drawings and includes a worm 41on the regulating wheel shaft meshing worm gear 42 mounted on spindle 43journaled in the bracket 44, depending from the regulating wheel slide19. Spindle 43 has keyed thereon the control cam 45 having a peripheralcam surface engaging roller 46 on lock plunger 47 which is rovided witha tooth head 48 inter- 35 of work carrier 31. This inter-lockingengagement thus secures the carrier against lorgitudinal movement.

am 45 is further provided with a guide ,teeth 34 on the carrier.

slot 49 for eccentric block50 whose position in the slot may be adjustedthrough the use of screw 51. Pivoted to this block is the push pawl 52shifted by spring 53 to engage the It will be understood that cam 45 isrotated continuously from th regulating wheel spindle and in thedirection indicated by the arrow thereon in Figure 4. As the cam rotatesa low point will come beneathroller 46 allowing the locking head 48tomove downward out of engagement with teeth 35. At the same time therotary movement of block 50 will shift pawl 52 to the left as viewed inFigure 4 and as the head 48 is disengaged pawl 52 will be ininterlocking engagement with one of the'teeth 34and as the cam continuesto rotate the pawl will press against the carrier moving sametransversely from front to rear of the machine carrying the work piecestherewith. At the completion of this pushing movement the locking headwill be again raised causing a dwell of the work piece between thewheels for .a completion of the grinding thereon, after whichthe'particular work piece will be carried on through the grinding throatfor discharge 'at a circumferentially advance point relative to thegrinding wheel as distinguished from a discharge of the work pieceaxially as occurs in the conventional type of centerless grinders.

In ordinary centerless grinding the work piece is engaged in the throatbetween grinding and regulating wheels in such manner that either by itsaxial introduction or by a decreasing in the operative width of thethroat a pressure is exerted by the grinding wheel against the work andthe stock removal takes lace.

In t e production of taper work, however, a difl'erent condition arisesdue to the fact that any pressure against the tapered sides of a workpiece would tend to squeeze out'the workpiece without grinding. In thepresent invention therefore, an over head member or bridge 54 isprovided in opposition to the work carrier guide 30. This bridge bearinga resiliently actuated shoe 55 disposed in salinement' with the narrowportion of the grinding throat between grinding and regulating wheels.As the/W013; is progressed alongits "guide .toward grin ing position theupper face of the work will be engaged by this shoe and the work piecepressed downward toward the beveled faces 15 and 26 of the grinding andregulating wheels. It will be noted this is a resilient pressure actionin which suflicient foree will be exerted to properly hold the 'workagainst the grinding wheel for stock removal and the regulating wheelfor frictional control of the work but at the same time there will be asufficient yielding action to compensate for thickness variations of thevalve heads. This is feasible since the prime essential in grinding avalve face is that a propersmooth surface of prescribed angle be formedand the matter of exact amount of stock removed or all alternate lengthor thickness is of secondary importance and can be otherwise readilytaken care of so long as a properly seating surface is produced.

It will be particularly noted that due to the cushion springs 410 thework pieces as they approach grinding position will be held with thesurface 17 to be ground at a suflicientheight to clear the outer edgesof the wheels as the work pieces enter the throat. Subsequently and asthe pieces are engaged by the shoe they are moved downwardly as theyshift inwardly and thus forced into proper grinding and controllingrelation with the respective wheels. As mentioned this is a yieldingaction pressing the valves downward in their guide bushings as stock isremoved from the valve face. This may be either an unlimited action orthe shoe may be provided with a stop flange 56-for inter-engagement withthe bridge 54 to limit the maximum downward movement that may beimparted to a work position.

The machine of Figures 6 and 7 is in general the same as that previouslydescribed, the distinction is that the grinding and regulating wheelsare of greater width providing the portions 15 and 25' respectively, sospaced that they will engage the stem portion of the valve, grinding thestem at the piece while in grinding same time that the seat is beingground on the mushroom head. In this instance the upper carrier portion31 is utilized, combined with lateral stem guiding or positioningmembers 57 and 58, formed as part of and movable with the carrier, Thework is then simultaneously ground as to stem and seat, insuringabsolute concentricity in these parts.

It will thus be seen that in the present machine the work is yieldinglysupported in suitable position forentrance into the glanding throat,that it is then progressively advanced into a portion of the throat ofdecreasing separation between the wheels and at the same time isresiliently axially shifted to press the work downward into the taperthroat provided-by the beveledsurface of the wheels so that the twowheels will suitably engage the work to grind and rotate the same.

It will further be noted that suitable means such as the guide bushing39 are provided for steadying the work piece against tllting actionduring the grinding thereof and that the yielding mounting of theregulating wheel additionally provides for a resilient follow-upengagement of the work by the J regulating wheel to insureproper controlof rotation of the work at all times during the grinding. I

I' claim: 1. A machine for the grinding of tapered articles comprising apair of opposed wheels having surfaces forming an included anglecorresponding to that to be produced on a work piece, means supporting awork piece for axial rotation,'one of said wheels being rotatable at arelatively slow-rate of speed to Control the rate of rotation of a workpiece engaged thereby, the other of said wheels being rotatableat agrinding rate of speed to generate the prescribed surface of revolutionon the work piece" as itis rotated about its axis by the slow movingwheel, and means for shifting a work piece transversely of said surfacein a plane bisecting the angle between said surfaces.

2. A machine for the grinding of tapered articles comprising a pair ofopposed wheels having surfaces formin corresponding to that to eproducedon awork piece, means supporting awork piece for.

axial rotation, one of said wheels being rotatable at a relatively slowrate of speed to control the rate of rotation of a work piece engagedthereby, the other of said wheels being rotatable at a grinding rate ofspeed to generate the prescribed surface of revolution on the work pieceas it is rotated about its axis by the slow moving wheel, means for anincluded angle 1 shifting awork piece transversely of said surface in aplane bisecting the angle betweensaid surfaces, and means for yieldinglyurging the work into engagement with the wheel surfaces.

3. A machine for the production of tapered work pieces comprising a pairoffrusto-conical wheels disposed adjacent each other to provide theprescribed included angle of taper therebetween, one of said wheelsbeing rotatable at ahigh grinding rate of spec and the other of saidwheels at a slow regulating speed for controlling the rota-i tion ofwork, means supporting the work for axial rotation as controlled by theslow moving wheel, means for advancing work and its supporting meanstransversely of said surfaces whereby the prescribed taper will begenerated on the work by the grinding wheel while pressed intoopposition thereto by the controlling wheel.

*piece with opposed portions of the surface to be operated'upqn by thegrinding wheel respectively engaged by the grinding and control wheelsfor moving the work piece transversely of said conical surfaces. in aplane normal to the common axial plane thereof.

5. A machine of the character described including opposed grinding andregulating wheels having active faces disposed at an angle one to theother for simultaneous engagement with different portions of a givensurface zone of the work piece whereby the related surfaces, means forresiliently urging a work piece axially into engagement with saidsurfaces and additional means for shifting the work across said surfacesin a direction at an angle to that of the resilient urge.

7. A machine for the production of tapered articles including a highspeed grinding wheel and an opposed slow speed regulating wheel forjointengagement with a work piece,

said wheels having angularly related operative faces, means forrotatably supporting a work piece with its axis of rotation bisectingthe angle between said faces, and means for urging the work pieceaxially whereby the same is forced into engagement with the operativefaces of the wheels.

8. A machine for the roduction of tapere articles including av igh speedgrinding wheel and an opposed 'slow speed regulating wheel for jointengagement with 'a work piece,

said Wheels having angularly related operative faces, means forrotatably supporting a work piece with its axis bisecting the anglebetween said faces, means for urging the work piece axially whereby thesame is forced into' engagement with the operative faces of the wheels,and additional means for shifting the axis of the work piece along theplane bisecting the included angle of the operative wheel faces.

9. A machine for the production of tapered articles such as valve seatfaces including a grinding wheel rotatable at a high grinding rate ofspeed and an opposed regulating .wheel rotatable at a slow workcontrolling rate'of s eed, said wheels having operative faces ma 'ngequal angles, with an intermediate bisecting plane, a work supportdisposed in said bisecting plane, and means for imparting anintermittent progressive movement to the work supportwhereby work piecescarried thereby are successively presented in operative relationv to thewheel faces.

10. A machine for the production of tapered articles such as-valve seatfaces ineluding a grinding wheel rotatable at a high grinding rate ofspeed and an opposed regulating wheel rotatable at aslowworkcontrolling'rate of s eed, said wheels having operative faces ma'ng equal angles with an intermediate bisecting 'p1a1 1e, awork supportd sposed in said bisecting plane, means for imparting an intermittentprogressive movement to the work support whereby work pieces carriedthereby are successively presented in operative relation to the wheelfaces, and means operating in an angularly related direction as respectsthe direction of I movement of the work support for holding anindividual work piece in contact'with'the angularly related wheelsurfaces at a given position during the movement of the work and itssupport.

11. A machine of cylindrical and tapered portions on a work forsimultaneous formation piece such as mushroomvalve comprising a grindingwheel operable at a high grinding rate of speed having a cylindricalperiphery for engagement with the valve stem and a conically taperedportion for engagement with the valve head, an opposed regulating wheeloperable at a slow rate of speed adapted to frictionally engage the workpiece and control the rate of rotation thereof, the 0pposed wheelsforming a successively narrowing and widening. throat, means forsteadya,

ing the work pieces against canting or displacementwithin the throat andmeans for progressing the work pieces laterally through the throat fromentrance to discharge side thereof.

12. A machine for the production of tapered work pieces including a pairof vertically mounted spindles having parallel axes, a grinding wheelcarried by one of said spindles rotatable in a horizontal plane at ahigh grinding rate of speed, a regulating wheel carried by the other ofsaid spindles and dis.- posed in oppositiontothe grinding wheel, saidregulating wheel bemg operable at a slow rate o'f speedto control therate ofrotation of a work piece in engagement there with, said wheelsbeing disposed in perlpheral opposition one to the other and beingbeveled at oneedge to form frustro-conical operative faces, a worksupport carried by the machine subtending the space between the opposedperipheries of the wheels, and means engageable with the work supportfor anally steadying a work piece at a "point remote from its engagementwith the frustro-conical' faces of the wheels. I 7

13. A machine for the production of ta pered work pieces including apair of verti.

carriedby the other of said spindles and disposed in opposition tothegrinding wheel,

grinding rate of speed, a regulating wheel said regulating wheel beingoperable at a slow rate of speed to control the rate of rotation of awork piece in engagement therewith, said wheels being disposed inperiph- 'eral opposition one to the other and being beveled at one edgeto form frustro-conical operative faces, a work support carried by themachine subtending the space between the opposed peripheries of thewheels, means engageable with the work support for axially steadying aWork piece at a point remote from its engagement with the frustroconicalfaces of the wheels, and means for advancing the work and its 'steadyingmember along the support to successively shift the work into and out ofengagement with said wheel faces.

14. A machine for the production of tapered Work pieces including a pairof vertically mounted spindles having parallel axes,

a grinding wheel carried by one of said spindles rotatable in ahorizontal plane at a high grinding rate of speed, a regulating wheelcarried by the other of said spindles and disposed in opposition to thegrinding wheel, said regulating wheel being operable at a slow rate ofspeed to control the rate of rdtation of a work piece in engagementtherewith, said wheels being disposed in peripheral opposition one tothe other and being beveled at one edge to form frustro-conicaloperative faces, ,a work support carried by the machine subtending thespace between the opposed peripheries of the wheels, means engageablewith the Work support for axially steadying a WOIkqPlt-ECG at a pointremote from its engagement with the frustro-conical faces of the wheels,means for advancing the work and itssteadying member supporttosuccessively shift the work into and out of engagement with said Wheelfaces, and means including adriven control member having alternatelyoperating shifting and locating means whereby the work advance and dwellis imparted to the work. 7

15. A machine of the character described including opposed grinding andregulating along the the. wheels substantially as and for the purpose,described.

In testimony whereof I affix my signature. RALPH MERSHON.

whels having active faces disposed at an angle one to the other ofprescribed taper for simultaneous engagement with opposed por tions ofthe work to be ground, means for rotatably supporting and advancing theWork while in engagement with said means Wherebythe one wheel will shapethe work to the prescribed form and the other wheel will controltherotation ther'eof during grinding, and means for, resiliently urging thework into engagement with the wheel surfaces to maintain contacttherebetween.

16. A machine of the character described including opposed grinding andregulating wheels having active faces disposed at an.

angle to one another simultaneously to engage a work piece surface withan included angle of prescribed taper, means for rotata-

